The present invention relates to an apparatus for transmitting torque from a driving shaft to a driven shaft, particularly an overrunning clutch, which comprises
at least one part, located within the clutch body, fitted with an internal engaging surface, whose center line deviates from the center line of the driving shaft, and with an external engaging surface, whose center line is the same as the center line of the driving shaft,
at least one engaging element, the first one on the driving shaft, which, at least when the clutch body is in the engaging position, engages with the internal engaging surface of the part within the clutch body, while said engagement makes the external engaging surface of the part within the clutch body engage with the internal engaging surface of the clutch body, and
at least one engaging element, the second one on the driving shaft, which, when the clutch body is in the disengaging position, engages with the part within the clutch body, and which engaging element, when the clutch body is in the engaging position, is disengaged from the part within the clutch body.
Torque is conventionally transmitted from a driving shaft to a driven shaft by means of various couplings and clutches. Among mechanical couplings and clutches, in which category the present invention can be classified, we know for instance rigid couplings, movable couplings, flexible couplings, releasing clutches and self-acting clutches. For instance U.S. Pat. No. 4,270,638 describes a device for transmitting torque from a driving shaft to a driven shaft, which device, depending on its purpose, may act as a releasing clutch, flexible coupling or a movable coupling. Generally speaking, a device in accordance with this patent may act as a mechanical stepless clutch. Said device comprises a clutch body, in which there is a part with an internal tooth ring, which part engages with the clutch body in an engaging situation. On the driving shaft there is a gear that meshes with the internal tooth ring. The internal tooth ring is installed eccentrically with regard to the driving shaft so that when the driving shaft is turned, the gear on the shaft forces the part with the tooth ring move in the direction of the radius of the shaft and engage with the clutch body.
In the device in accordance with this patent, there is also another engaging element, with which the device can be engaged in such a way that torque is not transmitted from the driving shaft to the clutch body; thence torque is not transmitted from the driving shaft to the driven shaft. However, the function of this second engaging element is not automated but has to be engaged separately. Therefore a device in accordance with this patent cannot work as an automatic overrunning clutch; instead, for this purpose it has to be fitted with engaging elements, with which the connection can be disengaged.